1. Field of the Invention
This invention relates to CNC tooling systems. More specifically, the present invention relates to a material marking system that incorporates an HMI device to allow a CNC operator to include additional marking information just prior to starting, or even during, a CNC tooling cycle.
2. Description of the Related Art
Computer numerical controlled (CNC) tooling systems are commonly used to automate manufacturing processes, such as the process of cutting a material into parts for later assembly. Typically, the tool (e.g., a plasma cutter, laser cutter, water jet cutter, band saw, etc.) is attached to a gantry assembly that is moveable in a horizontal plane (i.e., X-Y plane) proximal to the material to be worked. The work material is clamped to a tooling table, after which the CNC tooling system will move the gantry assembly and attached tool along a predetermined tool path necessary to perform the desired work.
In modern CNC tooling systems, end-to-end component design is highly automated using computer-aided drafting (CAD) programs. These programs produce a computer file that is interpreted to generate the commands needed to operate a particular make or model of CNC machine, and then loaded into the CNC machines for production.
For example, the typical CNC tooling process to cut parts from a material (e.g., sheet metal is as follows). First, a CAD draftsman draws the parts to be cut using a CAD program. Second, the CAD drawings are transferred into a nesting program that combines parts from the different part drawing files into a single nested drawing file with the parts arranged to fit on the source material, preferably in such a way so as to minimize waste. Third, the nested drawing file is sent to post-processing software, which converts the drawings into a command file containing specific codes interpretable by the CNC tooling system—also called G-code or preparatory code. Fourth, the command file is sent to the CNC tooling system, which interprets the code and makes the predetermined movements and/or performs the necessary work.
After the material is worked upon (e.g., cut into the desired shape and size), it is customary to mark the material with marking information, such as serial number, the run date, the manufacturer's name, material heat number, and the like. Typically, such marking is performed after the material is removed from the tooling table at a separate station, but moving the material to a different station prior to marking results in an increased likelihood of errors, lost parts, and the possibility of the material not being marked at all. Alternatively, some systems use the cutting tool of a CNC machine (e.g., a plasma torch) to mark parts during the CNC process. In such cases, the CAD draftsman includes the marking information in the part drawing file as a line drawing. During the post-processing step, the post-processing software embeds the marking information in the command file. This technique, however, requires the entire gantry cutting system to make very small and intricate moves to follow the tool path necessary to perform the marking. As a result, the marking is very rough, often has uneven marking depth, and can be difficult to read. Moreover, marking with this methodology is very slow, and offers no mechanism for the operator to input or modify marking information at the time of executing the tooling cycle.
U.S. Pat. No. 5,775,215 (issued Jul. 7, 1998) to Hirate, which is incorporated by reference herein, describes a machine tool with a marking apparatus that can mark parts-data on parts. A mount base is attached to the frame of the machine tool. A marking head is mounted on the mount base at a location other than the tooling location, and provides a pneumatic stylus movable within a horizontal plane.
One common problem with such marking systems as Hirate is that the CAD draftsman may not know all the marking information at the time the parts are drawn. For example, the CAD draftsman may not know the material to be used during the CNC tooling cycle, or the date the parts are to be cut, either of which could potentially be marked on the part. Thus, it would be advantageous to have a system and method that allows a CNC system operator to modify marking information at the time of tooling to include information not known at the time the part was drawn by the CAD draftsman.